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3.2 Volcanic Activity


Vocabulary


magma chamber- is a chamber that collects magma
pipe- a long tube that brings magma from the magma chamber to the Earth's surface
vent- the opening in the volcano that lets the magma out
lava flow- the place covered with lava when it comes out of the vent
crater- a area that is shaped like a bowl that can form around the volcano's vent
silica- is a material that is made out of the elements oxygen and silicon
pahoehoe- is lava that is moving fast
pyroclastic flow- occurs when an explosive eruption spurts out ash, cinder, bomb, in addition to gases
active- a volcano that may erupt in the future
dormant- a sleeping volcano
extinct- a dead volcano that might not erupt
hot spring- when groundwater is heated near magma the magma becomes a natural pool
geyser- a fountain in the ground that steams and erupt
geothermal energy- when water is heated by magma

Outline


How Minerals Form

  • Processes That Form Minerals
    • minerals can form in two ways
      • through crystallization of melted stuff
      • through crystallization of materials dissolved in H2O
  • Minerals From Magma
    • Large crystals form when magma cools slowly
    • Small crystals form when lava cools rapidly
  • Minerals from Hot Water Solutions
    • pure metals that crystallize underground from hot water usually form veins
    • ocean water seeps through cracks in earth's crust
      • water heats up after contacting the magma, then it dissolves minerals from the crust and rushes upward
  • Minerals Formed by Evaporation
    • minerals can form when solutions evaporate
      • Halite formed over millions of years when the ancient seas slowly evaporated
  • Where Minerals are Formed
    • less common or rare minerals are not distributed evenly throughout earth's crust
      • valuable minerals are found in or near areas of volcanic activity and mountain building
        • California's rich gold deposits were found along the Sierra Nevada mountain range
    • common minerals are distributed evenly throughout earth's crust